1. Separate research by both George Borjas, Robert W. Scrivner Professor of Economics and Social Policy at Harvard University and Paul Samuelson, Nobel Prize-winning economist from MIT has shown that illegal immigration had a substantial effect on reducing the economic status of U.S. poor while benefiting middle class individuals and wealthier Americans.http://old.nationalreview.com/issue/...0604250622.asp

2. Jeffrey Grogger (the Irving Harris Professor in Urban Policy in the Harris School at the University of Chicago), and Gordon H. Hanson (the Director of the Center on Pacific Economies and Professor of Economics at UCSD) suggests that a 10-percent immigrant-induced increase in the supply of a particular skill group reduced the black wage by 4.0 percent, lowered the employment rate of black men by 3.5 percentage points, and increased the incarceration rate of blacks by almost one percent.http://www.nber.org/papers/w12518

3. The nonpartisan Congressional Budget Office reviewed 29 reports published over 15 years to evaluate the impact of unauthorized immigrants on the budgets of state and local governments, and found that the tax revenues that unauthorized immigrants generate for state and local governments do not offset the total cost of services provided to those immigrants, but that the amount that state and local governments spend on services for unauthorized immigrants represents a small percentage of the total amount spent by those governments to provide such services to residents in their jurisdictions.http://www.cbo.gov/ftpdocs/87xx/doc8...mmigration.pdf

4. In 1999, law enforcement activities involving unauthorized immigrants in California, Arizona, New Mexico, and Texas cost a combined total of more than $108 million. This cost did not include activities related to border enforcement. In San Diego County, the expense (over $50 million) was nine percent of the total county's budget for law enforcement that year.
Report prepared for the United States/Mexico Border Counties Coalition February 2001

5. On August 6, 2008, an audit done by agents of Immigration and Customs Enforcement found that 137 of the 637 jail inmates in the Lake County, Illinois jail were illegal immigrants. According to Lake County sheriff Mark Curran, illegal immigrants were charged with half of the 14 murders in the countyhttp://www.dailyherald.com/story/?id=235885&src=3

7. Mohamed Atta al-Sayed and two of his co-conspirators had expired visas when they executed the September 11 attacks. All of the attackers had U.S. government issued documents and two of them were erroneously granted visa extensions after their deaths.http://archives.cnn.com/2002/US/03/1....school.visas/

8. Since the attacks of September 11, 2001, illegal immigrants within the United States have attempted to carry out other terrorist attacks as well. Three of the six conspirators in the 2007 Fort Dix attack plot--Dritan Duka, Shain Duka, and Eljvir Duka—were ethnic Albanians from the Republic of Macedonia who entered the United States illegally through Mexico. Hosam Maher Husein Smadi, an illegal immigrant from Jordan, was arrested in September 2009 for attempting to carry out a car bomb attack against Fountain Place in Dallas.

9. Indian, Russian, Thai, and Chinese women have been reportedly brought to the United States under false pretenses. “As many as 50,000 people are illicitly trafficked into the United States annually, according to a 1999 CIA study. Once here, they're forced to work as prostitutes, sweatshop laborers, farmhands, and servants in private homes.” US authorities call it “a modern form of slavery.”http://www.pbs.org/newshour/bb/law/j...avery_3-8.html

10. The presence of illegal immigrants and the exploitation of them drives down wages for certain sectors of the American populace, further widening the socioeconomic gulf between rich and poor.
Miller, Debra A."Illegal Immigration"(2007).Reference Point Press. 20-23